Where does it say that?
States, or are properly State Legislatures, don't have to allow voting at all in order to appoint their Electors. And, if they do, they can split the appointments among candidates, as Maine and Nebraska do already.
Okay Jim, then what good is the Electoral College?
Obviously it works, because Hillary isn’t president.
Trump won the majority of 49 states, but California was so lopsided that it tossed the result in the other 49 states out the window.
That’s exactly why we have it. Small states should have some say in things. Without it, they have nothing.
It was meant to avoid disenfranchisement.